A device using a compound (hereinafter sometime referred to as a “phosphorescent compound”), which emits light from a triplet excited state, as a luminescent material for use in a light-emitting layer of a light-emitting device, is known to have high luminous efficiency. When the phosphorescent compound is used in a light-emitting layer, usually a matrix is added to the compound to form a composition, which is used as a luminescent material. As the matrix, a polymer such as a polyvinylcarbazole is known to be suitably used, since it can form a thin film by coating (see, for example, Patent Document 1).